Carbon monoxide generation in fires: effect of temperature on halogenated and aromatic fuels

Abstract

Carbon monoxide is widely regarded as the major toxicant in fire effluents. It is produced as a result of incomplete combustion, by low temperatures, flame quenching, or under-ventilation. Polymers containing halogens and aromatic rings give higher carbon monoxide yields in well-ventilated conditions, when burnt in the steady state tube furnace (ISO 19700) at a furnace temperature of 650°C. This is believed to result from flame quenching by hydrogen halides or the enhanced stability of aromatic rings in flames, respectively. This work investigates the effect of ventilation condition and furnace temperature on the yield of carbon monoxide from burning mixtures of polyvinyl chloride and polyethylene, polyamide 6 containing a brominated flame retardant and an antimony synergist, and polystyrene. In each case, the high carbon monoxide yields in well-ventilated burning reduced at higher furnace temperatures, showing a diminution of both flame retardancy and fire toxicity above 850°C.